Particle size created by our VAT bottle is around 2.1?m (MMAD) tested by Cascade Impactor and 3.18?m tested at Dv(50) by Malvern Spraytec. Compared to most bottles in the market, our proprietary bottle ensures more efficient and effective performance. MMAD ? 3 ?m; Fine Particle Dose (FPD): 80-85% Consistent fine particle size for efficient respiratory treatment Patented Valve Adjustable nebulizer bottle (VAT) Low noise with silencer and vibration-absorber design Fine ventilation design to ensure heavy duty use Powerful Piston compressor Mouthpiece and masks for adult and child included Built-in nebulizer holder